Information processing apparatus, information processing method, and storage medium

ABSTRACT

Provided are an information processing apparatus, an information processing method, and a storage medium capable of acquiring feature information relating to sweat gland pores that can realize highly accurate identification of an individual. The information processing apparatus includes: a sweat gland pore extraction unit that extracts sweat gland pores from an image including a skin marking; and an information acquisition unit that acquires sweat gland pore information including position information about the sweat gland pore and directional information about the sweat gland pore for each of the sweat gland pores.

This application is a continuation of U.S. Ser. No. 17/610,762, filedNov. 12, 2021, which is a National Stage Entry of PCT/JP2019/021159filed on May 28, 2019, the contents of all of which are incorporatedherein by reference, in their entirety.

TECHNICAL FIELD

The disclosure relates to an information processing apparatus, aninformation processing method, and a storage medium.

BACKGROUND ART

PTL 1 discloses a method for identifying an individual by sweat glandsof a finger. In the method disclosed in PTL 1, a binarized image of afingerprint image is thinned and labeled, and a group in which thenumber of pixels in the labeling image is equal to or larger than apredetermined value is erased as a recess between fingerprint ridgelines, and the group remaining after the erasure is defined as a sweatgland, and the number is compared with a previously registered number tospecify an individual.

CITATION LIST Patent Literature

-   PTL 1: Japanese Patent No. 2859794-   PTL 2: Japanese Patent Application Laid-Open No. 2007-272775-   PTL 3: Japanese Patent Laid-Open No. H02-153478

SUMMARY Technical Problem

However, in the method disclosed in PTL 1, since the individual isidentified by comparing only the number of sweat glands, it is difficultto identify the individual with high accuracy.

It is an object of the disclosure to provide an information processingapparatus, an information processing method, and a storage mediumcapable of acquiring feature information relating to sweat gland poresthat can realize highly accurate identification of an individual, inview of the above-mentioned issues.

Solution to Problem

According to one aspect of the disclosure, there is provided aninformation processing apparatus including: a sweat gland poreextraction unit that extracts sweat gland pores from an image includinga skin marking; and an information acquisition unit that acquires sweatgland pore information including position information about the sweatgland pore and directional information about the sweat gland pore foreach of the sweat gland pores.

According to another aspect of the disclosure, there is provided aninformation processing method including: extracting sweat gland poresfrom an image including a skin marking; and acquiring sweat gland poreinformation including position information about the sweat gland poreand directional information about the sweat gland pore for each of thesweat gland pores.

According to another aspect of the disclosure, there is provided astorage medium storing a program that causes a computer to perform:extracting sweat gland pores from an image including a skin marking; andacquiring sweat gland pore information including position informationabout the sweat gland pore and directional information about the sweatgland pore for each of the sweat gland pores.

Advantageous Effects

According to the disclosure, it is possible to acquire featureinformation relating to sweat gland pores that can realize highlyaccurate identification of an individual.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram illustrating a configuration of an informationprocessing apparatus according to a first example embodiment.

FIG. 2 is a flowchart illustrating an operation of acquiring sweat glandpore information in the information processing apparatus according tothe first example embodiment.

FIG. 3A shows an example of a fingerprint image taken by the fingerprintimaging unit.

FIG. 3B shows an example of a fingerprint image taken by the fingerprintimaging unit.

FIG. 4A is a schematic diagram illustrating an example of fingerprintimage segmentation processing in the information processing apparatusaccording to the first example embodiment.

FIG. 4B is a schematic diagram illustrating another example of thefingerprint image segmentation processing in an information processingapparatus according to first example embodiment.

FIG. 5 is a schematic diagram illustrating an example of sweat glandpore extraction processing by an O-ring in the information processingapparatus according to first example embodiment.

FIG. 6 is a schematic diagram illustrating an example of the sweat glandpore extraction processing by a C-ring in the information processingapparatus according to the first example embodiment.

FIG. 7 is a schematic diagram illustrating processing for acquiringdirection information of sweat gland pores in the information processingapparatus according to the first example embodiment.

FIG. 8A is a schematic diagram illustrating an example of positioninformation, direction information, and error tolerance range includedin sweat gland pore information acquired in an information processingapparatus according to first example embodiment.

FIG. 8B is a schematic diagram illustrating an example of positioninformation, direction information, and error tolerance range includedin sweat gland pore information acquired in an information processingapparatus according to first example embodiment.

FIG. 9 is a flowchart illustrating matching operation in an informationprocessing apparatus according to a second example embodiment.

FIG. 10 is a schematic diagram illustrating an example of matchingprocessing based on position information of sweat gland pores in theinformation processing apparatus according to the second embodiment.

FIG. 11 is a schematic diagram illustrating an example of matchingprocessing based on direction information of sweat gland pores in theinformation processing apparatus according to the second exampleembodiment.

FIG. 12 is a flowchart illustrating a drawing operation of a quasi ridgeline in an information processing apparatus according to a third exampleembodiment.

FIG. 13 is a schematic diagram illustrating an example of connectionprocessing at an intersection in the drawing operation of the quasiridge line in the information processing apparatus according to thethird example embodiment.

FIG. 14 is a schematic diagram illustrating an example of the quasiridge drawn by the connection processing at an intersection in thedrawing operation of the quasi ridge in the information processingapparatus according to the third example embodiment.

FIG. 15 is a schematic diagram illustrating an example of branchconnection processing in the drawing operation of the quasi ridge linein the information processing apparatus according to the third exampleembodiment.

FIG. 16 is a schematic diagram illustrating an example of the connectionprocessing using a valley line in the drawing operation of the quasiridge line in the information processing apparatus according to thethird example embodiment.

FIG. 17A is a schematic diagram illustrating an example of determinationprocessing of a non-valley line portion in the drawing operation of thequasi ridge line in the information processing apparatus according tothe third example embodiment.

FIG. 17B is a schematic diagram illustrating an example of thedetermination processing of the non-valley line portion in the drawingoperation of the quasi ridge line in the information processingapparatus according to the third example embodiment.

FIG. 18 is a schematic diagram illustrating an example of interruptionprocessing of drawing in the drawing operation of the quasi ridge linein the information processing apparatus according to the third exampleembodiment.

FIG. 19A is a schematic diagram illustrating another example of thebranch connection processing in the drawing operation of the quasi ridgeline in the information processing apparatus according to the thirdexample embodiment.

FIG. 19B is a schematic diagram illustrating another example of thebranch connection processing in the drawing operation of the quasi ridgeline in the information processing apparatus according to the thirdexample embodiment.

FIG. 20 is a schematic diagram illustrating an example of stopprocessing of the drawing at an endpoint in the drawing operation of thequasi ridge line in the information processing apparatus according tothe third example embodiment.

FIG. 21 is a block diagram illustrating a configuration of aninformation processing apparatus according to another exampleembodiment.

DESCRIPTION OF EMBODIMENTS First Example Embodiment

An information processing apparatus and an information processing methodaccording to a first example embodiment of the disclosure will bedescribed with reference to FIGS. 1 to 8B.

First, the configuration of the information processing apparatusaccording to the example embodiment will be described with reference toFIG. 1 . FIG. 1 is a block diagram illustrating a configuration of theinformation processing apparatus according to the example embodiment.

As illustrated in FIG. 1 , the information processing apparatus 1according to the example embodiment includes a CPU (Central ProcessingUnit) 10, a RAM (Random Access Memory) 12, a storage unit 14, an inputunit 16, a fingerprint imaging unit 18, and a display unit 20. The CPU10, the RAM 12, the storage unit 14, the input unit 16, the fingerprintimaging unit 18, and the display unit 20 are connected to the common bus22.

The information processing apparatus 1 is not particularly limited, butis, for example, a computer apparatus such as a laptop or desktoppersonal computer. The information processing apparatus 1 may be, forexample, a smartphone, a tablet type personal computer, or the like.

The CPU 10 operates by executing the program stored in the storage unit14, and functions as a control unit for controlling the operation of theentire information processing apparatus 1. The CPU 10 executes a programstored in the storage unit 14 to perform various processes as theinformation processing apparatus 1. The RAM 12 provides a memory areanecessary for the operation of the CPU 10. Specifically, the CPU 10executes a program stored in the storage unit 14 to function as afunctional unit as described below.

The information processing apparatus 1 according to the exampleembodiment functions as a feature information acquisition apparatus foracquiring and registering sweat gland pore information which is featureinformation relating to the sweat gland pore imaged on a fingerprintimage of a finger of a target person to be registered from thefingerprint image. Since the CPU 10 of the information processingapparatus 1 functions as a feature information acquisition apparatus,the CPU 10 functions as an image acquisition unit 102, an image divisionunit 104, a sweat gland pore extraction unit 106, a direction detectionunit 108, an error setting unit 110, a reliability acquisition unit 112,and a registration unit 114, as will be described later. The sweat glandpore extraction unit 106 and the direction detection unit 108 functionas an information acquisition unit for acquiring sweat gland poreinformation for each sweat gland pore. The information processingapparatus 1 functioning as the feature information acquisition apparatuswill be described in the example embodiment.

The information processing apparatus 1 also functions as a matchingapparatus for identifying the target person by performing matching ofthe sweat gland pore information of the target person to be identifiedand the sweat gland pore information of the registered registrant. Inorder to function as the matching apparatus, the CPU 10 of theinformation processing apparatus 1 functions as a matching unit 116 anda determination unit 118, as will be described later. The informationprocessing apparatus 1 functioning as matching apparatus will bedescribed with reference to a second example embodiment.

Further, the information processing apparatus 1 also functions as aridge line drawing apparatus for drawing a quasi ridge line which is apseudo ridge line based on sweat gland pore information acquired fromthe fingerprint image. Since the CPU 10 of the information processingapparatus 1 functions as the ridge line drawing apparatus, it functionsas the ridge line drawing unit 120 as will be described later. Theinformation processing apparatus 1 functioning as a ridge line drawingapparatus will be described with reference to the third exampleembodiment.

The storage unit 14 comprises a storage medium such as a non-volatilememory such as a flash memory, a hard disk drive, or the like. Thestorage unit 14 stores programs executed by the CPU 10, data referred toby the CPU 10 when the programs are executed, and the like.

The storage unit 14 stores a sweat gland pore information database (DB,Database) 142. The sweat gland pore information DB 142 registers sweatgland pore information acquired from a fingerprint image of a finger ofa registrant associated with personal information of the registrant. Theregistered sweat gland pore information that is sweat gland poreinformation registered in the sweat gland pore information DB 142 ismatched with sweat gland pore information acquired from a fingerprintimage of a finger of a target person to be identified when identifyingthe target person.

An input unit 16 receives input of information, instructions, etc., froman operator to the information processing apparatus 1. The operator caninput an instruction for execution of processing and various kinds ofinformation to the information processing apparatus 1 via the input unit16. The input unit 16 is not particularly limited, but includes, forexample, a keyboard, a mouse, and the like. The input unit 16 may beformed of, for example, a touch panel incorporated in the display unit20.

The fingerprint imaging unit 18 is a fingerprint imaging device thatimages the belly of a finger of a target person to acquire a fingerprintimage. The fingerprint imaging unit 18 images a fingerprint imageincluding not only ridge lines and valleys but also sweat gland pores.The fingerprint imaging unit 18, for example, can image a fingerprint byreceiving near-infrared light emitted from a finger, which enters afinger placed with its belly facing the imaging surface of the imagesensor, is scattered in the finger, and is then received by the imagesensor. The fingerprint imaging unit 18 can adjust the position of thefingerprint in the image area of the fingerprint image to a specificposition, for example, by a guide structure for guiding and regulatingthe position of the finger when the finger is placed on the imagingsurface. The method by which the fingerprint imaging unit 18 acquiresthe fingerprint image is not particularly limited as long as thefingerprint image including sweat gland pores can be acquired, andvarious methods can be employed.

The display unit 20 displays a screen such as a screen of a program forexecuting various processes in accordance with control by the CPU 10.The display unit 20 includes, for example, a liquid crystal display, anOLED (Organic Light Emitting Diode) display, and the like. The displayunit 20 may be built in the information processing apparatus 1, which isa laptop or tablet personal computer, or may be an external displayprovided separately from the information processing apparatus 1. Thedisplay unit 20 may be constituted by a touch panel display in which atouch panel serving as an input unit 16 is incorporated.

It should be noted that some or all of the functions of the respectiveunits in the information processing apparatus 1 described above need notnecessarily be implemented by a single apparatus, but may be implementedby another external apparatus such as a server. For example, some or allof the functions of the respective units of the CPU 10 may be realizedby a CPU of a server communicatively connected to the informationprocessing apparatus 1 via a network. For example, the storage unit 14may be realized by a storage device of a server, a network storage, orthe like, which is communicatively connected to the informationprocessing apparatus 1 via a network.

Thus, the information processing apparatus 1 according to the exampleembodiment is configured.

Fingerprints have the inequality of all people, which varies from personto person, and the constancy of life, which does not change throughoutlife. Therefore, fingerprints have come to be widely used in situationswhere individual identification is required. However, it has beendifficult to extract fingerprint-related features for newborns andinfants using conventional techniques.

In contrast, the information processing apparatus 1 according to theexample embodiment acquires sweat gland pore information includingposition information about the sweat gland pores and directioninformation about the sweat gland pores for each of the sweat glandpores as feature information about the sweat gland pores included in thefingerprint image, as will be described below. The informationprocessing apparatus 1 according to the example embodiment can acquiresweat gland pore information from a fingerprint image of a finger of anewborn infant or an infant. The ridge lines of the fingerprint arecontinuous ridge lines containing sweat gland pores. The location andother characteristics of the sweat glands associated with these ridgelines also vary from person to person. Therefore, the sweat gland poreinformation acquired by the information processing apparatus 1 accordingto the example embodiment can be used for identifying an individualincluding a newborn infant and an infant. Furthermore, since the sweatgland pore information includes not only position information but alsodirection information, it is possible to specify an individual with highaccuracy.

It should be noted that the information processing apparatus 1 accordingto the example embodiment can acquire sweat pore information not only onthe fingers of newborn infants and infants but also on the fingers ofpersons of all ages.

The finger for acquiring sweat the gland pore information is notparticularly limited. The information processing apparatus 1 accordingto the example embodiment can acquire the sweat gland pore informationon any finger from which a fingerprint image has been acquired. Forexample, the information processing apparatus 1 can acquire the sweatgland pore information from a fingerprint image of one or more fingersout of a total of 10 fingers of the thumb, index finger, middle finger,ring finger, and little finger of each of a left hand and a right hand.Also, not only the finger, for example, the information processingapparatus 1 can acquire the sweat gland pore information from the finger(toe) mark image for one or a plurality of toes among a total of 10 toesincluding the first toe, the second toe, the third toe, the fourth toe,and the fifth toe of each of a left foot and a right foot. Furthermore,the information processing apparatus 1 can acquire sweat gland poreinformation not only on the fingers and toes but also on any partincluding sweat gland pores and forming patterns on the skin. Theinformation processing apparatus 1 can acquire sweat gland poreinformation from an image including skin markings other thanfingerprints. The skin marking may include any part of the skin pattern,such as fingerprints, palms, footprints, etc.

Hereinafter, the acquisition operation for acquiring the sweat glandpore information in the information processing apparatus 1 according tothe example embodiment will be described with reference to FIGS. 2 to8B. FIG. 2 is a flowchart illustrating an operation of acquiring thesweat gland pore information in the information processing apparatus 1.FIG. 3A is a diagram illustrating an example of a fingerprint imagetaken by the fingerprint imaging unit 18. FIG. 3B is an enlarged view ofa rectangular area in the fingerprint image shown in FIG. 3A. FIG. 4A isa schematic diagram illustrating an example of the division processingof the fingerprint image in the information processing apparatus 1. FIG.4B is a schematic diagram illustrating another example of the divisionprocessing of the fingerprint image in the information processingapparatus 1. FIG. 5 is a schematic diagram illustrating an example ofextraction processing of sweat gland pores by an O-ring in theinformation processing apparatus 1. FIG. 6 is a schematic diagramillustrating an example of extraction processing of sweat gland pores bya C-ring in the information processing apparatus 1. FIG. 7 is aschematic diagram illustrating acquisition process of the directioninformation of the sweat gland pore in the information processingapparatus 1. FIGS. 8A and 8B are schematic diagrams illustrating anexample of position information, direction information, and errortolerance range included in the sweat gland pore information acquired inthe information processing apparatus 1. The information processingapparatus 1 according to the example embodiment operates to execute aninformation processing method according to the example embodiment foracquiring the sweat gland pore information.

First, as illustrated in FIG. 2 , the fingerprint imaging unit 18 imagesa fingerprint of a finger of a target person to register sweat glandpore information (step S102). Thus, the fingerprint imaging unit 18acquires and outputs a fingerprint image including sweat gland pores ofthe target person.

As shown in FIGS. 3A and 3B, the fingerprint image F imaged by thefingerprint imaging unit 18 is an image in which the fingerprint isimaged in the rectangular image area A. The fingerprint in thefingerprint image F is imaged so that the longitudinal direction of thefinger is along a pair of sides in the longitudinal direction of theimage area A. The fingerprint image F is, for example, a 256 gradationimage having pixel values corresponding to the unevenness of the bellyof the fingertip. In the fingerprint image F, pixels with higher heightsare brighter pixels with higher pixel values. In this case, in thefingerprint image F, ridge lines are displayed brighter, valley linesare displayed darker, and sweat gland pores are displayed darker. In thefingerprint image F, the sweat gland pores are dark granular areasarranged in ridge lines which are bright linear areas sandwiched betweenvalley lines which are dark linear areas. The correspondence between theunevenness of the belly of the fingertip and the pixel values may beopposite, and the pixels with higher heights may be darker pixels withlower pixel values. In the following description, a case will bedescribed in which, in the fingerprint image, the higher the height, thebrighter the pixel whose pixel value is higher.

When the fingerprint image is imaged by the fingerprint imaging unit 18,the CPU 10 executes the following processing by the functional unitrealized by the execution of the program.

First, as illustrated in FIG. 2 , the image acquisition unit 102acquires the fingerprint image output by the fingerprint imaging unit 18(step S104). When the position of the fingerprint in the image area ofthe fingerprint image does not match a specific position, the imageacquisition unit 102 can prompt the user to re-image the fingerprintimage by, for example, displaying a message on the display unit 20. Inthis case, the image acquisition unit 102 can also perform imageprocessing for correcting the fingerprint image so that the fingerprintposition matches a specific position.

Instead of acquiring the fingerprint image output by the fingerprintimaging unit 18, the image acquisition unit 102 may acquire thefingerprint image by reading the fingerprint image from the storagemedium or by receiving the fingerprint image via the network.

Next, the image division unit 104 divides the fingerprint image acquiredby the image acquisition unit 102 (step S106). Thus, the image divisionunit 104 divides the image area of the fingerprint image into aplurality of divided areas which are smaller than the image area.

As shown in FIGS. 4A and 4B, for example, the image division unit 104can divide the image area A of the fingerprint image F into rectangulardivided areas Pik in a grid shape. Herein, i is a positive integersatisfying 1≤i≤m, where m is an integer of 2 or more. k is a positiveinteger satisfying 1≤k≤n, where n is an integer of 2 or more. FIGS. 4Aand 4B show a case where m and n are 3, respectively. The plurality ofdivided areas Pik have the same rectangular shape. In FIGS. 4A and 4B,the ridge lines are shown in black, and the valleys and sweat glandpores are shown in white for convenience in the fingerprint image.

As shown in FIG. 4A, the image division unit 104 can divide the imagearea A of the fingerprint image F so that adjacent divided areas do notoverlap each other. Further, as illustrated in FIG. 4B, the imagedivision unit 104 can divide the image area A of the fingerprint image Fso that portions of the adjacent divided areas overlap each other. FIG.4B shows a case where half of the divided areas adjacent to each otheroverlap.

It is not necessary for the image division unit 104 to divide the imagearea A of the fingerprint image F into a plurality of divided areas ofthe same shape. The image division unit 104 can divide the image area Aof the fingerprint image F into a plurality of divided areas havingmutually different shapes. The shape of the divided area is not limitedto a rectangular shape, and various shapes can be adopted.

Next, the sweat gland pore extraction unit 106 extracts a plurality ofsweat gland pores from the divided area of the fingerprint image dividedby the image division unit 104 (step S108). The sweat gland poreextraction unit 106 can extract the sweat gland pore in the followingmanner.

First, as illustrated in FIG. 5 , the sweat gland pore extraction unit106 detects a granular area that fits in the O-ring OR, which is aclosed circular ring having a diameter in a predetermined range, in thedivided area Pik based on the information on the gradation in thedivided area Pik of the fingerprint image. The granular area detectedhere is an area in a predetermined gradation range, that is, an area inwhich the height composed of pixels having a predetermined pixel valueor less is a predetermined height or less. To fit in the O-ring OR meansthat a granular area enters the O-ring OR without contacting the O-ringOR. The sweat gland pore extraction unit 106 can detect a granular areawhile changing the diameter of the O-ring OR within a predeterminedrange. The sweat gland pore extraction unit 106 extracts the granulararea detected by an O-ring OR as a sweat gland pore. In FIG. 5 , foursweat gland pores are extracted by O-ring OR, and the other sweat glandpores are extracted in the same manner.

In the extraction of sweat gland pores by the O-ring OR, a granular areaisolated from the valley line can be extracted as a sweat gland pore. Onthe other hand, in the fingerprint image, a sweat gland pore may beimaged as a granular area connected to the valley line. In theextraction of sweat gland pores by the O-ring OR, it is impossible todetect the granular area connected to the valley line.

Therefore, as illustrated in FIG. 6 , the sweat gland pore extractionunit 106 further detects a granular area that fits in the C-ring CR,which is a partially open circular ring having a predetermined range ofdiameter in the divided area Pik, based on the information on thegradation in the divided area Pik of the fingerprint image. The C-ringCR is a circular ring having one open portion of a predetermined rangeof length. The granular area detected here is an area in a predeterminedgradation range, that is, an area in which the height composed of pixelshaving a predetermined pixel value or less is a predetermined height orless. To fit in the C-ring CR means that a granular area enters insidethe C-ring CR without contacting the C-ring CR, and a connection partwith a valley line of the granular area enters an open portion of theC-ring CR. The sweat gland pore extraction unit 106 can change thediameter of the C-ring CR and the length of the open portion in apredetermined range, and detect a granular area while changing theposition of the open portion in the C-ring CR. The sweat gland poreextraction unit 106 also extracts the granular area detected by theC-ring CR as a sweat gland pore. FIG. 6 shows a state in which foursweat gland pores are extracted by the C-ring CR in addition to the foursweat gland pores extracted by the O-ring OR, and the other sweat glandpores are extracted in the same manner.

Thus, the sweat gland pore extraction unit 106 extracts sweat glandpores not only by using the O-ring OR but also by using the C-ring CR,so that the sweat gland pores can be extracted with high accuracy. Thesweat gland pore extraction unit 106 extracts the sweat gland poresusing the O-ring OR first as described above, or extracts the sweatgland pores using the C-ring CR first among the extractions of the sweatgland pores using the O-ring and the C-ring. In addition, the sweatgland pore extraction unit 106 can execute both extraction of the sweatgland pore using the O-ring OR and extraction of the sweat gland poreusing the C-ring CR in parallel. In addition, the sweat gland poreextraction unit 106 can extract sweat gland pores from the divided areasby various methods in addition to the above-described method.

Although the sweat gland pore extraction unit 106 uses the O-ring OR,which is a closed ring, and the C-ring CR, which is a partially openring, for extracting the sweat gland pore, the ring for extracting thesweat gland pore does not necessarily have to be a circular ring. Thesweat gland pore extraction unit 106 can use rings of various shapes asclosed rings or partially open rings for extracting sweat gland poresfor extracting sweat gland pore.

Further, as illustrated in FIG. 2 , the sweat gland pore extraction unit106 functions as an information acquisition unit for acquiring positioninformation relating to the sweat gland pore, and acquires positioninformation of the sweat gland pore for each of the plurality ofextracted sweat gland pores (step S110). In acquiring the positioninformation, the sweat gland pore extraction unit 106 calculates thecoordinates of the center of gravity of the granular area extracted asthe sweat gland pore in the two-dimensional coordinate system set in thefingerprint image. The sweat gland pore extraction unit 106 acquirescoordinate information showing the calculated coordinates of the centerof gravity as the coordinate information of the sweat gland pore, whichis position information of the sweat gland pore. Thus, the sweat glandpore extraction unit 106 can acquire the coordinate information of thecenter of gravity of the sweat gland pore as the position information ofthe sweat gland pore.

Note that the sweat gland pore extraction unit 106 can acquire not onlycoordinate information of the center of gravity of the sweat gland porebut also coordinate information of a specific position of the sweatgland pore as the position information of the sweat gland pore. Theposition information of the sweat gland pore may be such that theposition of the sweat gland pore can be identified.

Next, the error setting unit 110 sets an error tolerance range for theposition information of the sweat gland pore acquired by the sweat glandpore extraction unit 106 (step S112). The error setting unit 110 can seta range of a predetermined distance or less from the coordinates of thesweat gland pore as an error tolerance range. The error setting unit 110can relatively set an error tolerance range according to the image sizeof the fingerprint image.

Next, the direction detection unit 108 functions as an informationacquisition unit for acquiring direction information relating to thesweat gland pore, and acquires the direction information of the sweatgland pore for each of the plurality of the sweat gland pores extractedby the sweat gland pore extraction unit 106 (step S114).

In acquiring the direction information, the direction detection unit 108specifies the positions of the valley lines V on both sides located inthe vicinity of the center of gravity G of the sweat gland pore SP inthe ridge line R, as illustrated in FIG. 7 . Next, the directiondetection unit 108 acquires the directions d1 and d2 of the valley linesV on both sides at the identified nearest position. Next, as thedirection information of the sweat gland pore SP, the directiondetection unit 108 acquires information indicating the direction Dobtained by averaging the directions d1 and d2, that is, vectorinformation relating to a vector indicating the direction D and passingthrough the center of gravity G. The direction of the vector in thevector information indicating the direction D can be set arbitrarily oraccording to a certain rule as either one of the direction along thedirection D and the opposite direction.

The direction detection unit 108 can acquire, as the directioninformation of the sweat gland pore, not only information indicating theaveraged direction of the valley lines on both sides located nearest tothe center of gravity of the sweat gland pore but also informationindicating the direction related to the sweat gland pore. The directioninformation of the sweat gland pore may be a direction related to thesweat gland pore such as a direction at the position of the sweat glandpore of the ridge line where the sweat gland pore is located and adirection corresponding to the shape of the sweat gland pore.

Next, as illustrated in FIG. 2 , the error setting unit 110 sets anerror tolerance range for the direction information of the sweat glandpore acquired by the direction detection unit 108 (step S116). The errorsetting unit 110 can set, as the error tolerance range, a range of notmore than a predetermined angle with the direction indicated by thedirection information of the sweat gland pore as the center. In thisway, the error tolerance ranges are set for the position information andthe direction information of the sweat gland pore information.Therefore, even when the finger is deformed or displaced uponacquisition of the fingerprint image, the position information and thedirectional information can be appropriately matching by absorbingerrors caused by the finger's deformation or displacement.

As described above, the error setting unit 110 does not necessarily setthe error tolerance ranges for both the position information and thedirection information of the sweat gland pore information. The errorsetting unit 110 can set an error tolerance range to at least one of theposition information and the direction information of the sweat glandpore information.

Thus, the sweat gland pore extraction unit 106 and the directiondetection unit 108 function as a feature information acquisition unitfor acquiring sweat gland pore information which is feature informationrelating to the sweat gland pore, and acquires sweat gland poreinformation including position information and direction information.The sweat gland pore information includes the error tolerance range setfor the position information and the error tolerance set for thedirection information.

FIGS. 8A and 8B schematically show sweat gland pore information FSobtained for sweat gland pores extracted in divided areas Pik. The sweatgland pore information FS includes coordinate information of the centerof gravity G of the sweat gland pore as the position information of thesweat gland pore. For the coordinate information of the center ofgravity G, the error tolerance range E1 indicating a range of apredetermined distance or less from the coordinate of the center ofgravity G which is the coordinate of the sweat gland pore is set. Thesweat gland pore information FS includes vector information indicatingthe direction D obtained by averaging the directions of the valley lineson both sides located near the nearest side as the direction informationof the sweat gland pore. For the vector information indicating thedirection D, the error tolerance range E2 indicating a range of apredetermined angle or less around the direction D is set.

Note that the timings at which the steps S110 to S116 are executed arenot limited to the above case. For example, each time a sweat gland poreis extracted in step S108, the steps S110 to S116 may be executed. Forexample, after steps S110 and S114 are executed, steps S112 and S116 maybe executed.

Next, the reliability acquisition unit 112 acquires reliabilityinformation indicating reliability for the divided area from which thesweat gland pore information has been acquired (step S118). Thereliability acquisition unit 112 can acquire, for example, thereliability information indicating higher reliability of the dividedarea as the number of sweat gland pores extracted in the divided areabecomes larger. Further, the reliability acquisition unit 112 canacquire the reliability information indicating lower reliability of thedivided area, for example, as the area of the area where the pixel valuein the divided area is equal to or smaller than a predeterminedthreshold value and where there is no fingerprint is wider. Thereliability acquisition unit 112 can acquire reliability informationbased on at least either the number of sweat gland pores or the area ofthe area without fingerprint. The reliability acquisition unit 112acquires, as the reliability information of the divided area, areliability score that is a score having a larger value as thereliability of the divided area is higher. The reliability score may bea score having a smaller value as the reliability of the divided area ishigher.

The timing at which the step S118 is executed is not limited to theabove case. For example, it may be performed following step S108 ofextracting the sweat gland pores.

Next, the CPU 10 determines whether or not the processes in steps S108to S118 have been completed for all the divided areas of the fingerprintimage (step S120). If it is determined that the processes have not beencompleted for all the divided areas (step S120, NO), the CPU 10 executesthe processing of steps S108 to S118 for the divided areas whoseprocessing has not been completed.

On the other hand, if it is determined that the processes have beencompleted for all the divided areas (step S120, YES), the registrationunit 114 registers the sweat gland pore information acquired for thefingerprint image in the sweat gland pore information DB 142 in thestorage unit 14 (step 122). At the time of registration, theregistration unit 114 registers an identification number for uniquelyidentifying the target person whose fingerprint image was acquired, thesweat gland pore information acquired for each divided area of thefingerprint image, the reliability information of each divided area, andpersonal information of the target person in association with eachother. The personal information is, for example, a name, a sex, a dateof birth, a contact, etc. The personal information is inputted, forexample, by an operator to the information processing apparatus 1through the input unit 16.

Thus, the information processing apparatus 1 can acquire and registerthe sweat gland pore information including the position information andthe direction information relating to the sweat gland pores as thefeature information relating to the sweat gland pores extracted from thefingerprint image for the target person.

In the sweat gland pore information DB 142, sweat gland pore informationof a plurality of registrants is registered and stored by executing theprocessing for a plurality of target persons.

As described above, according to the example embodiment, the sweat glandpore information including not only the position information about thesweat gland pores but also the direction information about the sweatgland pores is acquired as feature information, so that it is possibleto acquire the feature information relating to the sweat gland poresthat can realize highly accurate identification of an individual.

Second Example Embodiment

An information processing apparatus and an information processing methodaccording to a second example embodiment of the disclosure will bedescribed with further reference to FIGS. 9 to 11 . Note that the samecomponents as those in the information processing apparatus and theinformation processing method according to the first example embodimentdescribed above are labeled with the same references, and thedescription thereof will be omitted or simplified. In exampleembodiment, the information processing apparatus 1 functioning as amatching apparatus for identifying a target person by performingmatching of the sweat gland pore information of the target person to beidentified and the registered sweat gland pore information of theregistrant will be described. Since the CPU 10 of the informationprocessing apparatus 1 according to the example embodiment functions asmatching apparatus, the CPU 10 further functions as the matching unit116 and the determination unit 118, as illustrated in FIG. 1 . Thematching unit 116 includes a position matching unit 1162 and a directionmatching unit 1164.

The number of sweat gland pores in a fingerprint is distributed in aspecific range according to race. For this reason, it is considered tobe difficult to identify individuals with high accuracy simply bymatching the number of sweat gland pores. In contrast, in the exampleembodiment, the sweat gland pore information, which is the featureinformation including a plurality of pieces of information such as theposition information and the direction information, is matched, so thatit is possible to identify an individual with high accuracy.

The matching operation in the information processing apparatus 1according to the example embodiment will be described below withreference to FIGS. 9 to 11 . FIG. 9 is a flowchart illustrating thematching operation in the information processing apparatus 1. FIG. 10 isa schematic diagram illustrating an example of the matching processingbased on the position information of the sweat gland pores in theinformation processing apparatus 1. FIG. 11 is a schematic diagramillustrating an example of the matching processing based on thedirection information of the sweat gland pores in the informationprocessing apparatus 1. The information processing apparatus 1 accordingto the example embodiment operates to execute an information processingmethod according to the example embodiment for matching the sweat glandpore information.

The information processing apparatus 1 acquires the sweat gland poreinformation, the reliability information, and the like by performingsteps S102 to S120 illustrated in FIG. 2 for a fingerprint image of atarget person to be identified by matching the sweat gland poreinformation, as in the case of the first example embodiment.

When target sweat gland pore information which is the sweat gland poreinformation of the target person is acquired from a fingerprint image ofthe target person to be identified, the CPU 10 performs the followingprocesses by functional units realized by executing a program tomatching the sweat gland pore information.

First, as illustrated in FIG. 9 , matching unit 116 acquires targetsweat gland pore information (step S202).

Next, matching unit 116 reads out and acquires registered sweat glandpore information, which is the sweat gland pore information of theregistrant registered in the sweat gland pore information DB 142 of thestorage unit 14, from the sweat gland pore information DB 142 (stepS204).

The matching unit 116 performs matching for each divided areacorresponding to the target sweat gland pore information and theregistered sweat gland pore information. Prior to matching for eachdivided area, the matching unit 116 determines a non-matching dividedarea, which is a divided area for which matching of the sweat gland poreinformation is not performed, based on the reliability information ofboth divided areas corresponding to each other of the target sweat glandpore information and the registered sweat gland pore information (stepS206). That is, the matching unit 116 determines both divided areas asthe non-matching divided areas when the reliability information of oneof the two divided areas corresponding to the target sweat gland poreinformation and the registered sweat gland pore information shows lowthe reliability below a certain level. For example, if one of thereliability scores is equal to or less than a predetermined thresholdvalue and indicates a low reliability equal to or less than apredetermined value, the matching unit 116 can determine both dividedareas as the non-matching divided areas. Thus, the matching unit 116matches the sweat gland pore information about the divided areas havinga predetermined reliability or higher among the plurality of dividedareas.

The matching unit 116 matches the target sweat gland pore informationand the registered sweat gland pore information for each division areacorresponding to each other except the determined non-matching divisionarea as follows.

First, the position matching unit 1162 matching the position informationof the sweat gland pore included in the divided area of the target sweatgland pore information and the position information of the sweat glandpore included in the divided area of the corresponding registered sweatgland pore information (step S208). Hereinafter, the divided area of thetarget sweat gland pore information is appropriately referred to as thetarget divided area, and the divided area of the registered sweat glandpore information is appropriately referred to as the registered dividedarea. The position matching unit 1162 determines whether or not theposition information of the sweat gland pore included in the targetdivision area and the position information of the sweat gland poreincluded in the registered division area coincide with each other withinerror tolerance ranges set respectively. Thus, the position matchingunit 1162 identifies the set of sweat gland pores matching the positioninformation within the error tolerance ranges. As described above, sincethe position information is matched in consideration of the errortolerance range, even when deformation or displacement of the fingeroccurs in acquiring the fingerprint image, the position information canbe appropriately matching by absorbing errors due to deformation ordisplacement of the finger.

Specifically, as illustrated in FIG. 10 , the position matching unit1162 matches the position information of the sweat gland poreinformation tFS of the sweat gland pore tSP included in the targetdivided area tPik and the position information of the sweat gland poreinformation rFS of the sweat gland pore rSP included in the registereddivided area rPik. The position matching unit 1162 matches the positioninformation of the sweat gland pore information tFS and the positioninformation of the sweat gland pore information rFS about the set of thesweat gland pores tSP, rSP which may correspond to each other.

Next, as illustrated in FIG. 9 , the direction matching unit 1164matches the direction information about the set of sweat gland pores ofwhich the position information coincides within the error toleranceranges (step S210). The direction matching unit 1164 determines whetheror not the direction information of the sweat gland pore included in thetarget divided area and the direction information of the sweat glandpore included in the registered divided area coincide with each otherwithin error tolerance ranges set for each set of the sweat gland pores.Thus, the direction matching unit 1164 identifies a set of sweat glandpores in which the direction information coincides within errortolerance ranges. As described above, since the direction information ismatched in consideration of the error tolerance range, even whendeformation, displacement or the like of the finger occurs in acquiringthe fingerprint image, the direction information can be appropriatelymatched by absorbing errors due to deformation, displacement or the likeof the finger.

Specifically, as illustrated in FIG. 11 , the direction matching unit1164 matches the direction information of the sweat gland poreinformation tFS and the direction information of the sweat gland poreinformation rFS about the set of the sweat gland pore tSP and rSP whoseposition information coincides within the error tolerance ranges.

Next, as illustrated in FIG. 9 , based on the results of the matchingperformed by the position matching unit 1162 and the direction matchingunit 1164, the matching unit 116 calculates a matching score for eachdivided area showing the matching result (step S212). The matching unit116 calculates a higher area-specific matching score as the number ofsets of the sweat gland pores in which both the position information andthe direction information coincide within the error tolerance rangesbecomes larger. Note that the elevation of the area-specific matchingscore may be reversed. That is, the matching unit 116 can also calculatea lower area-specific matching score as the number of sets of thematched sweat gland pore becomes larger. In this case, for thereliability score of the divided area, a score having a smaller valuecan be used as the reliability score of the divided area becomes higher.

Next, the matching unit 116 determines whether or not the processes insteps S208 to S212 have been completed for all divided areas except thenon-matching divided areas (step S214). If it is determined that theprocesses have not been completed for all the divided areas (step S214,NO), the matching unit 116 executes the processes of steps S208 to S212for the divided areas for which processing has not been completed.

On the other hand, when it is determined that the processes have beencompleted for all the divided areas (Step S214, YES), the matching unit116 acquires the reliability information for each of the target dividedareas and the registration divided areas excluding the non-matchingdivided areas (step S216).

Next, the matching unit 116 calculates a total matching score reflectingthe reliability information based on the area-specific matching scoreand the reliability information (step S218). The matching unit 116 cancalculate the total matching score as follows. First, the matching unit116 calculates a weighted score for each of the area-specific matchingscores calculated for each divided area by multiplying the area-specificmatching scores by the reliability scores of the corresponding targetdivided areas and the registration divided areas. Then, the matchingunit 116 sums the weighted scores calculated for each of matching scoresby area to calculate the total matching score.

When calculating the weighted score, the matching unit 116 can multiplyvarious weights instead of multiplying the area-specific matching scoreby the reliability scores of the target divided area and theregistration divided area as weights. For example, the matching unit 116may multiply the area-specific matching score for each area by a lowerscore of either the reliability score of the target divided area or thereliability score of the registered divided area as a weight. Further,for example, the matching unit 116 can also multiply the area-specificmatching score for each area by the average value of the reliabilityscore of the target divided area and the reliability score of theregistered divided area as a weight.

The determination unit 118 determines whether or not the target personis a registrant based on the total matching score calculated by thearea-specific matching score which is the matching result for eachdivided area and the reliability score which is reliability informationof the divided area as follows.

First, the determination unit 118 determines whether or not the totalmatching score calculated by matching unit 116 is equal to or greaterthan a predetermined threshold (step S220). In the case where the heightof matching score for each area is reversed as described above, thedetermination unit 118 can determine by reversing the comparison withthe threshold value.

If it is determined that the total matching score is not less than apredetermined threshold value (step S220, YES), the determination unit118 determines that matching of the target sweat gland pore informationand the registered sweat gland pore information coincide (step S222). Inthis case, the determination unit 118 determines that the target personto be identified is a registrant of the registered sweat gland poreinformation who has performed matching, and specifies the target person.

Next, the determination unit 118 outputs the matching result indicatingthat the target sweat gland pore information coincides with theregistered sweat gland pore information and information about theregistrant of the registered sweat gland pore information coincidingwith the target sweat gland pore information (step S224). Thedetermination unit 118 can acquire and output, as the matching result,the personal information of the registrant associated with theregistered sweat gland pore information matching the target sweat glandpore information from the sweat gland pore information DB 142. Thedetermination unit 118 can output the total matching score as thematching result. The determination unit 118 can display matching resulton the display unit 20 and output the matching result, for example. Thedetermination unit 118 can also output, for example, the matching resultby voice from a speaker (not shown).

The determination unit 118 can output a probability indicating that thetarget person is a registrant based on the total matching score, insteadof identifying the target person as a registrant.

Thus, the determination unit 118 can identify the target person fromwhom the target sweat gland pore information has been acquired as theregistrant of the registered sweat gland pore information that matchesthe target sweat gland pore information.

On the other hand, if it is determined that the total matching score isless than a predetermined threshold value (step S220, NO), thedetermination unit 118 determines that matching of the target sweatgland pore information and the registered sweat gland pore informationdo not coincide (step S226). In this case, the determination unit 118determines that the target person to be identified is not a registrantof the registered sweat gland pore information for which the matching isperformed.

Next, the determination unit 118 outputs the matching result indicatingthat the target sweat gland pore information does not match theregistered sweat gland pore information (step S228). The determinationunit 118 can output the total matching score as the matching result. Thedetermination unit 118 can display the matching result on the displayunit 20 and output the matching result, for example. The determinationunit 118 can also output, for example, the matching result by voice froma speaker (not shown). The determination unit 118 may omit the output ofmatching result when the target sweat gland pore information does notmatch the registered sweat gland pore information.

Next, the determination unit 118 determines whether or not matching withthe matching targets of the plurality of registered sweat gland poreinformation registered in the sweat gland pore information DB 142 iscompleted (step S230). The determination unit 118 can set all of theplurality of registered sweat gland pore information registered in thesweat gland pore information DB 142 as the matching target. Further, thedetermination unit 118 can narrow down a part of the plurality ofregistered sweat gland pore information to be the matching target. Thedetermination unit 118 can narrow down the matching targets by using,for example, information such as gender and date of birth included inthe personal information of the registrant associated with theregistered sweat gland pore information.

When it is determined by the determination unit 118 that the matching isnot completed (Step S230, NO), the CPU 10 proceeds to step S204, andexecutes the matching of the target sweat gland pore information withthe registered sweat gland pore information which is not matched.

On the other hand, when the determination unit determines that thematching has been completed (step S230, YES), the determination unit 118outputs a failure result indicating that the identification of thetarget person from which the target sweat gland pore information hasbeen acquired has failed (step S232). The determination unit 118 candisplay the failure result on the display unit 20 and output the failureresult, for example. In addition, the determination unit 118 can output,for example, a failure result by voice from a speaker (not shown).

As described above, according to example embodiment, the sweat glandpore information including the position information and the directioninformation relating to the sweat gland pore is matched to identify thetarget person, so that it is possible to identify an individual withhigh accuracy.

Third Example Embodiment

An information processing apparatus and an information processing methodaccording to a third example embodiment of the disclosure will bedescribed further with reference to FIGS. 12 to 20 . Note that the samecomponents as those in the information processing system and theinformation processing method according to the first and second exampleembodiments described above are labeled with the same references, andthe description thereof will be omitted or simplified.

In the example embodiment, the information processing apparatus 1functioning as a ridge line drawing apparatus for drawing a quasi ridgeline, which is a quasi ridge line, based on the sweat gland poreinformation including the position information and the directioninformation acquired from a fingerprint image will be described. Theinformation processing apparatus 1 draws the thinned quasi ridge line.Since the CPU 10 of the information processing apparatus 1 according tothe example embodiment functions as a ridge line drawing apparatus, theCPU 10 further functions as the ridge line drawing unit 120, asillustrated in FIG. 1 . The drawing of the quasi ridge line includesgenerating image data of the quasi ridge line, storing the image data ofthe generated image in a storage medium such as the RAM 12 or thestorage unit 14, and displaying the quasi ridge line on the display unit20.

Hereinafter, the drawing operation of the quasi ridge line in theinformation processing apparatus 1 according to the example embodimentwill be described with reference to FIGS. 12 to 20 . FIG. 12 is aflowchart illustrating the drawing operation of the quasi ridge line inthe information processing apparatus 1. FIG. 13 is a schematic diagramillustrating an example of connection processing at an intersection inthe drawing operation of the quasi ridge line in the informationprocessing apparatus 1. FIG. 14 is a schematic diagram illustrating anexample of the quasi ridge line drawn by connection processing at anintersection in the drawing operation of the quasi ridge line in theinformation processing apparatus 1. FIG. 15 is a schematic diagramillustrating an example of branch connection processing in the drawingoperation of the quasi ridge line in the information processingapparatus 1. FIG. 16 is a schematic diagram illustrating an example ofconnection processing using a valley line in a drawing operation of aquasi ridge line in the information processing apparatus 1. FIGS. 17Aand 17B are schematic diagrams illustrating an example of thedetermination processing of the non-valley line portion in the drawingoperation of the quasi ridge line in the information processingapparatus 1. FIG. 18 is a schematic diagram illustrating an example ofinterruption processing of drawing in the drawing operation of the quasiridge line in the information processing apparatus 1. FIGS. 19A and 19Bare schematic diagrams illustrating another example of the branchconnection processing in the drawing operation of the quasi ridge linein the information processing apparatus 1. FIG. 20 is a schematicdiagram illustrating an example of the stop processing of the drawing atan endpoint in the drawing operation of the quasi ridge line in theinformation processing apparatus 1. The information processing apparatus1 according to the example embodiment operates to execute an informationprocessing method according to the example embodiment for drawing thequasi ridge line.

The information processing apparatus 1 executes steps S102 to S120illustrated in FIG. 2 to acquire the sweat gland pore information, thereliability information, and the like, as in the case of the firstexample embodiment, for the fingerprint image of the target person onwhich the quasi ridge line is to be drawn. The information processingapparatus 1 can draw the quasi ridge line following the registration ofthe sweat gland pore information by the first example embodiment. Itshould be noted that the information processing apparatus 1 does notnecessarily need to acquire the reliability information when drawing thequasi ridge line. The information processing apparatus 1 can also readout and acquire the sweat gland pore information of the target personfrom the sweat gland pore information DB 142 or the like in the storageunit 14.

When the sweat gland pore information is acquired from a fingerprintimage of a target person to draw the quasi ridge line, the CPU 10 drawsthe quasi ridge line by executing the following processing by afunctional unit realized by execution of a program. The CPU 10 can drawthe quasi ridge line for the entire fingerprint image, or can draw thequasi ridge line for a part of a plurality of divided areas obtained bydividing the fingerprint image, for example, a divided area having areliability score equal to or higher than a predetermined value.

First, as illustrated in FIG. 12 , the ridge line drawing unit 120acquires the sweat gland pore information acquired from the fingerprintimage of the target person (step S302).

Next, the ridge line drawing unit 120 identifies two sweat gland poreslocated adjacent to each other in the same ridge line based on theposition information included in the sweat gland pore information (stepS304).

Next, the ridge line drawing unit 120 calculates, for each of theidentified two sweat gland pores, an extension line that is a straightline corresponding to the position information and the directioninformation included in the sweat gland pore information (step S306). Inthis case, specifically, as illustrated in FIG. 13 , the ridge linedrawing unit 120 calculates the extension line EL along the direction Dpassing through the center of gravity G of the sweat gland pore SP asthe extension line according to the position information and thedirection information included in the sweat gland pore information,based on the sweat gland pore information FS of the sweat gland pore SP.Thus, the ridge line drawing unit 120 calculates the extension linewhich is a straight line passing through the position indicated by theposition information and along the direction indicated by the directioninformation.

The ridge line drawing unit 120 draws the quasi ridge line in thefollowing manner based on the extension line which is a straight linecorresponding to the position information and the direction informationof the sweat gland pore information thus calculated.

First, as illustrated in FIG. 12 , the ridge line drawing unit 120determines whether or not the extension lines corresponding to theposition information and the direction information of the two identifiedsweat gland pores intersect in the ridge line where both of the sweatgland pores are located without crossing over the valley line (stepS308). Specifically, as illustrated in FIG. 13 , the ridge line drawingunit 120 determines whether or not the extension line EL of one sweatgland pore SP of the two identified sweat gland pores SP intersects theextension line EL of the other sweat gland pore SP within the ridge lineR.

As shown in FIG. 12 , when it is determined that the extension linesintersect within the ridge line (Step S308, YES), the ridge line drawingunit 120 draws the quasi ridge line connecting the two sweat gland poresthrough the intersection of the extension lines (step S310). In thiscase, specifically, as illustrated in FIG. 13 , the extension line EL ofone sweat gland pore SP out of the two identified sweat gland pores SPintersects the extension line EL of the other sweat gland pore SP at theintersection PX within the ridge line R where both sweat gland pores SPare located. The ridge line drawing unit 120 draws a line segmentconnecting the center of gravity G of one sweat gland pore SP and anintersection PX and a line segment connecting the intersection PX andthe center of gravity G of the other sweat gland pore SP as a quasiridge line QR. FIG. 14 shows an example in which the quasi ridge line QRis drawn for the divided area Pik shown in FIG. 8A or the like. FIG. 14shows a case where the quasi ridge line QR is drawn for a part of thesweat gland pores.

Thus, the ridge line drawing unit 120 draws the quasi ridge line QRconnecting one sweat gland pore SP and the other sweat gland pore SPthrough the intersection PX where the extension line EL of one sweatgland pore SP intersects with the extension line EL of the other sweatgland pore SP.

Further, as illustrated in FIG. 12 , the ridge line drawing unit 120determines whether it is possible to connect a branching quasi ridgeline to the drawn quasi ridge line (step S312). In this case,specifically, as illustrated in FIG. 15 , the ridge line drawing unit120 determines whether one of the two extension lines EL intersecting atthe intersection PX intersects the extension line EL of the furtherother sweat gland pore SP within the ridge line R where the respectivesweat gland pores SP are located. If it is determined that the linesintersect each other, the ridge line drawing unit 120 determines thatthe branching quasi ridge lines can be connected.

As illustrated in FIG. 12 , when it is determined that the branchingquasi ridge line can be connected (step S312, YES), the ridge linedrawing unit 120 draws the branching quasi ridge line connected to thedrawn quasi ridge line (step S314). In this case, specifically, asillustrated in FIG. 15 , one of the two extension lines EL intersectingat the intersection PX further intersects at the intersection PX withthe extension line EL of the further other sweat gland pore SP.Regarding the intersection at this intersection PX, the ridge linedrawing unit 120 draws a line segment connecting the center of gravity Gof one sweat gland pore SP and the intersection PX and a line segmentconnecting the intersection PX and the center of gravity G of the othersweat gland pore SP as a quasi ridge line QR. Thus, the ridge linedrawing unit 120 draws the branching quasi ridge line QR.

The processes in steps S312 and S314 can be executed independently ofthe series of processes shown in FIG. 12 .

Next, as illustrated in FIG. 12 , the ridge line drawing unit 120determines whether or not the drawing of the quasi ridge line has beencompleted (step S316). If it is determined that the drawing has not beencompleted (step S316, NO), the ridge line drawing unit 120 proceeds tostep S304 to continue drawing the quasi ridge line. When it isdetermined that the drawing has been completed (step S316, YES), theridge line drawing unit 120 ends the drawing of the quasi ridge line.

If it is determined that the branching quasi ridge cannot be connected(step S312, NO), the ridge line drawing unit 120 proceeds to step S316and executes the same processing as described above.

On the other hand, if it is determined that the extension lines do notintersect within the ridge line (step S308, NO), the ridge line drawingunit 120 determines whether or not it is possible to draw a quasi ridgeline connecting the sweat gland pores by using the valley line (stepS318). When the extension lines do not intersect in the ridge line, asillustrated in FIG. 16 , the extension line EL of one sweat gland poreSP intersects the valley line V at the intersection PV. The extensionline EL of the other sweat gland pore SP intersects the valley line V atanother intersection PV. When the length of the valley line V betweenthe two intersections PV is equal to or less than a predeterminedthreshold, the ridge line drawing unit 120 determines that a quasi ridgeline connecting the two sweat gland pores SP can be drawn by using thevalley line V. On the other hand, if the length of the valley line Vbetween the two intersections PV exceeds a predetermined threshold, theridge line drawing unit 120 determines that it is impossible to draw aquasi ridge line connecting the two sweat gland pores SP by using thevalley line V. When a quasi ridge line cannot be drawn using the valleyline V, the extension line EL of the sweat gland pore SP usually crossesthe valley line V in a state orthogonal to or close to the intersection.

As shown in FIG. 12 , when it is determined that the quasi ridge linecan be drawn using the valley line (step 318, YES), the ridge linedrawing unit 120 draws the quasi ridge line connecting the sweat glandpores using the valley line (step S320). In this case, specifically, asillustrated in FIG. 16 , the ridge line drawing unit 120 draws a linesegment connecting the center of gravity G of the sweat gland pore SPand the intersection PV and a portion between the two intersections PVof the valley line V as the quasi ridge line QR. The line segmentconnecting the center of gravity G of the sweat gland pore SP and theintersection PV is a line segment connecting the center of gravity G ofone sweat gland pore SP and the intersection PV of the extension line ELand a line segment connecting the center of gravity G of the other sweatgland pore SP and the intersection PV of the extension line EL.

Thus, the ridge line drawing unit 120 draws the quasi ridge line QRconnecting one sweat gland pore SP and the other sweat gland pore SPthrough the valley line V between the intersection PV where theextension line EL of one sweat gland pore SP intersects with the valleyline V and the intersection PV where the extension line EL of the othersweat gland pore SP intersects with the valley line V.

Next, the ridge line drawing unit 120 proceeds to step S312 and executesthe same processing as described above.

On the other hand, when it is determined that the quasi ridge linecannot be drawn using the valley line (step S318, NO), the ridge linedrawing unit 120 determines whether or not the linear portion treated asthe valley line crossing the extension line of the sweat gland pore is anon-valley line portion (step S322). The non-valley line portion has thesame gradation as the valley line in the fingerprint image, but isactually a portion which is not a valley line, for example, wrinkles,scratches, dust, etc.

More specifically, as illustrated in FIGS. 17A and 17B, the ridge linedrawing unit 120 compares the width Wx of the linear portion LX, whichis treated as the valley line intersecting at the intersection PV withthe extension line EL of the sweat gland pore SP, with the width Wr ofthe ridge line R where the sweat gland pore SP of the extension line ELis located. The ridge line drawing unit 120 can calculate, as the widthWr of the ridge line R, for example, the interval between the valleylines V on both sides of the nearest vicinity of the sweat gland poreSP. The ridge line drawing unit 120 can calculate, as the width Wr ofthe ridge line R, for example, the average value of the width of apredetermined range of the ridge line R where the sweat gland pore SP islocated. Further, the ridge line drawing unit 120 can calculate thewidth of the linear portion LX in the same direction as the width Wr ofthe ridge line R, as the width Wx of the linear portion LX. Although thelinear portion LX may be curved or bent, FIGS. 17A and 17B show thelinear portion LX as a line segment along the same direction as thewidth Wr of the ridge line R for convenience. The ridge line drawingunit 120 determines whether or not the linear portion LX is a non-valleyline part based on a result of comparing the width Wx of the linearportion LX with the width Wr of the ridge line R.

First, as illustrated in FIG. 17A, when the width Wx of the linearportion LX is larger than the width Wr of the ridge line R, that is,when Wx>Wr, the ridge line drawing unit 120 determines that the linearportion LX is a non-valley line portion. In this case, since the widthWx of the linear portion LX is larger than the width Wr of the ridgeline R, there is a high probability that the linear portion LX is anon-valley line portion such as a wrinkle.

As shown illustrated in FIG. 17B, when the width Wx of the linearportion LX is smaller than a predetermined ratio of the width Wr of theridge line R, that is, when Wx<α×Wr, the ridge line drawing unit 120determines that the linear portion LX is a non-valley line portion.Here, α is a coefficient satisfying 0<α<1. The value of α can be setappropriately, for example, α=0.5. In this case, since the width Wx ofthe linear portion LX is smaller than a predetermined ratio of the widthof the ridge line R, there is a high probability that the linear portionLX is a non-valley line portion such as a dust.

On the other hand, when none of the above is satisfied, that is, whenα×Wr≤Wx≤Wr, the ridge line drawing unit 120 determines that the linearportion LX is not a non-valley line portion. In this case, the linearportion LX is a valley line and is an end point at which the quasi ridgeline stops if the connection of the branching quasi ridge line is notpossible as described later.

As illustrated in FIG. 12 , when the linear portion is determined to bea non-valley line portion as described above (step S322, YES), the ridgeline drawing unit 120 determines that the linear portion is not treatedas a valley line and proceeds to step S304. Thus, the ridge line drawingunit 120 ignores the linear portion determined as the non-valley lineportion and again executes the drawing of the quasi ridge line.

On the other hand, if it is determined that the linear portion is notthe non-valley portion (step S322, NO), the ridge line drawing unit 120draws a quasi ridge line up to the intersection with the linear portionand interrupts drawing of the quasi ridge (step S324). In this case,specifically, as illustrated in FIG. 18 , the ridge line drawing unit120 draws a quasi ridge line QR connecting the intersection PV of theextension line EL of the sweat gland pore SP and the linear portion LXand the center of the gravity G of the sweat gland pore SP. Thus, theridge line drawing unit 120 draws the quasi ridge line QR up to theintersection PV and interrupts drawing of the quasi ridge line QR.

Next, as illustrated in FIG. 12 , the ridge line drawing unit 120determines whether it is possible to connect a branching quasi ridgeline to the quasi ridge line of which drawing has been interrupted (stepS326). In this case, specifically, as illustrated in FIG. 19A, the ridgeline drawing unit 120 sets a virtual area VA corresponding to the widthWr of the ridge line R around the quasi ridge line QR of which drawingis interrupted. The virtual area VA can be set, for example, as an areain which the distance from the quasi ridge line QR is less than half thewidth Wr of the ridge line R. The ridge line drawing unit 120 determineswhether an end part of a virtual area VA of a specific quasi ridge lineQR overlaps with an end part of a virtual area VA of another quasi ridgeline QR. The ridge line drawing unit 120 determines that the specificquasi ridge line QR line can be connected as a quasi ridge linebranching the other two quasi ridge lines QR when the ends of the othertwo virtual areas VA in opposite directions overlap with the end of thespecific virtual area VA from both sides.

As illustrated in FIG. 12 , when it is determined that it is possible toconnect the branching quasi ridge line (step S326, YES), the ridge linedrawing unit 120 connects the branching quasi ridge line to the quasiridge of which drawing has been interrupted (step S328). In this case,specifically as illustrated in FIG. 19B, the ridge line drawing unit 120connects, with respect to the specific quasi ridge line QR, the othertwo quasi ridge lines QR where the virtual areas VA overlap as branchingquasi ridge lines to draw them. The ridge line drawing unit 120 canredraw the quasi ridge line QR so that the connected quasi ridge line QRbecomes smooth.

Thus, the ridge line drawing unit 120 draws the branching quasi ridgeline based on the overlapping of the end portions of the virtual areawhich is an area set around the drawn quasi ridge line.

Next, as illustrated in FIG. 12 , the ridge line drawing unit 120proceeds to step S316 and executes the same processing as describedabove.

On the other hand, if it is determined that the branching quasi ridgecannot be connected (step S326, NO), the ridge line drawing unit 120stops drawing the quasi ridge of which drawing has been interrupted(step S330). In this case, specifically, as illustrated in FIG. 20 , theridge line drawing unit 120 stops drawing the quasi ridge line QR withthe intersection PV with the valley line which serves as the end of thequasi ridge line QR as an endpoint.

Next, as illustrated in FIG. 12 , the ridge line drawing unit 120proceeds to step S316 and executes the same processing as describedabove.

Note that the processes from steps S322 to S330 can be executedindependently of the series of processes illustrated in FIG. 12 when alinear portion crossing the extension line of the sweat gland pore in astate orthogonal thereto or close to the orthogonal to thereto isdetected.

Thus, the ridge line drawing unit 120 draws the thinned quasi ridge linebased on the position information and the direction information of thesweat gland pore included in the sweat gland pore information in thefingerprint image from which the sweat gland pore information has beenacquired. The ridge line drawing unit 120 can store the image data ofthe drawn quasi ridge in the storage unit 14 in association with thesweat gland pore information used for drawing. The drawn quasi ridgelines can be used, for example, for a fingerprint matching by a minutiasystem, a pattern matching system or the like.

Thus, according to the example embodiment, since the quasi ridge line isdrawn based on the sweat gland pore information including the positioninformation and the direction information of the sweat gland pore, it ispossible to draw the thinned ridge line with high accuracy.

In the example embodiment, quasi ridge lines are drawn based on thesweat gland pores themselves, so that the sweat gland pores are noterroneously detected as discontinuous valley lines. Therefore, in theexample embodiment, since the ridge line is not erroneously divided bythe mis-detected valley line, it is possible to realize the drawing ofthe quasi ridge line with high accuracy. Especially in newborns andinfants, sweat gland pores are often mis-detected as discontinuousvalley lines because the width of sweat gland pores is relatively largecompared to the width of valley lines. Even in such cases, according tothe example embodiment, the thinned ridge lines can be drawn with highaccuracy.

Other Example Embodiment

The information processing apparatus described in the exampleembodiments may be configured as illustrated in FIG. 21 according toanother example embodiment. FIG. 21 is a block diagram illustrating aconfiguration of an information processing apparatus according toanother example embodiment.

As illustrated in FIG. 21 , the information processing apparatus 1000according to another example embodiment includes a sweat gland poreextraction unit 1002 that extracts sweat gland pores from an imageincluding a skin marking. The information processing apparatus 1000includes an information acquisition unit 1004 that acquires sweat glandpore information including position information about the sweat glandpore and direction information about the sweat gland pore for each ofthe sweat gland pores.

According to the information processing apparatus 1000 provided byanother example embodiment, the sweat gland pore information includingnot only the position information about the sweat gland pores but alsothe direction information about the sweat gland pores is acquired asfeature information, so that it is possible to acquire the featureinformation relating to the sweat gland pores that can realize highlyaccurate identification of an individual.

Modified Example Embodiment

The disclosure is not limited to the example embodiments describedabove, and various modifications are possible.

For example, in the example embodiments described above, the case wherea fingerprint image is imaged by the fingerprint imaging unit 18 isdescribed as an example, but the disclosure is not limited thereto. Theinformation processing apparatus 1 may not have a fingerprint imagingunit 18. In this case, the fingerprint image is imaged by a fingerprintimaging device which is a device separate from the informationprocessing apparatus 1. The information processing apparatus 1 can beconfigured, for example, to read and acquire a fingerprint image from astorage medium storing the fingerprint image imaged by a fingerprintimaging device, or to receive and acquire a fingerprint image via anetwork.

In addition, in the example embodiments described above, the process ofdividing the fingerprint image into the plurality of divided areas andacquiring sweat gland pore information is performed as an example, butthe disclosure is not limited to this. The information processingapparatus 1 can also execute processing for acquiring sweat gland poreinformation without dividing the fingerprint image into a plurality ofdivided areas.

In addition, in the example embodiments described above, the case wherethe sweat gland pore information is acquired from the fingerprint imageis described as an example, but the disclosure is not limited thereto.The information processing apparatus 1 acquires the sweat gland poreinformation from an image including a skin marking of an area includingthe sweat gland pores and forming a pattern on the skin, in addition toa fingerprint image, performs matching of the sweat gland poreinformation, and performs drawing of the quasi ridge line.

Further, the scope of each of the example embodiments includes aprocessing method that stores, in a storage medium, a program thatcauses the configuration of each of the example embodiments to operateso as to implement the function of each of the example embodimentsdescribed above, reads the program stored in the storage medium as acode, and executes the program in a computer. That is, the scope of eachof the example embodiments also includes a computer readable storagemedium. Further, each of the example embodiments includes not only thestorage medium in which the computer program described above is storedbut also the computer program itself.

As the storage medium, for example, a floppy (registered trademark)disk, a hard disk, an optical disk, a magneto-optical disk, a compactdisc-read only memory (CD-ROM), a magnetic tape, a nonvolatile memorycard, or a ROM can be used. Further, the scope of each of the exampleembodiments includes an example that operates on operating system (OS)to perform a process in cooperation with another software or a functionof an add-in board without being limited to an example that performs aprocess by an individual program stored in the storage medium.

The whole or part of the example embodiments disclosed above can bedescribed as, but not limited to, the following supplementary notes.

(Supplementary Note 1)

An information processing apparatus comprising:

a sweat gland pore extraction unit that extracts sweat gland pores froman image including a skin marking; and

an information acquisition unit that acquires sweat gland poreinformation including position information about the sweat gland poreand directional information about the sweat gland pore for each of thesweat gland pores.

(Supplementary Note 2)

The information processing apparatus according to supplementary note 1,

wherein the information acquisition unit acquires the directioninformation based on directions of valley lines on both sides of a ridgeline where the sweat gland pore is located.

(Supplementary Note 3)

The information processing apparatus according to supplementary note 1or 2,

wherein the sweat gland pore extraction unit extracts the sweat glandpore based on information relating to gradation of the image.

(Supplementary Note 4)

The information processing apparatus according to supplementary note 3,

wherein the sweat gland pore extraction unit extracts an area of apredetermined gradation range that fits in a closed ring in the image asthe sweat gland pore.

(Supplementary Note 5)

The information processing apparatus according to supplementary note 3or 4,

wherein the sweat gland pore extraction unit extracts an area of apredetermined gradation range that fits in a ring partially opened inthe image as the sweat gland pore.

(Supplementary Note 6)

The information processing apparatus according to any one ofsupplementary notes 1 to 5, further comprising an error setting unitthat sets an error tolerance range for at least one of the positioninformation and the direction information.

(Supplementary Note 7)

The information processing apparatus according to any one ofsupplementary notes 1 to 6, further comprising a matching unit thatmatches first sweat gland pore information acquired on the first imageand second sweat gland pore information acquired on the second image.

(Supplementary Note 8)

The information processing apparatus according to supplementary note 7,

wherein the matching unit matches the first position information of thefirst sweat gland pore information and the second position informationof the second sweat gland pore information.

(Supplementary Note 9)

The information processing apparatus according to supplementary note 7or 8,

wherein the matching unit matches the first direction information of thefirst sweat gland pore information and the second direction informationof the second sweat gland pore information.

(Supplementary Note 10)

The information processing apparatus according to any one ofsupplementary notes 7 to 9, further comprising:

an image division unit that divides the image into a plurality ofdivided areas; and

a reliability acquisition unit that acquires reliability informationabout reliability of the divided area according to the number of thesweat gland pores extracted in the divided area,

wherein the matching unit matches the sweat gland pore information aboutthe divided area having a predetermined reliability or higher among theplurality of divided areas.

(Supplementary Note 11)

The information processing apparatus according to supplementary note 10,further comprising a determination unit that determines whether or not atarget person from whom the first image has been acquired is aregistrant from whom the second image has been acquired, based on amatching result for each of the divided areas by the matching unit andthe reliability information of the divided area.

(Supplementary Note 12)

The information processing apparatus according to any one ofsupplementary notes 1 to 11,

wherein the position information is coordinate information of the centerof gravity of the sweat gland pore.

(Supplementary Note 13)

The information processing apparatus according to any one ofsupplementary notes 1 to 12,

wherein the direction information is information indicating a directionobtained by averaging directions of valley lines on both sides locatednearest to the center of gravity of the sweat gland pore.

(Supplementary Note 14)

The information processing apparatus according to any one ofsupplementary notes 1 to 13, wherein the skin marking is a fingerprint.

(Supplementary Note 15)

An information processing method comprising:

extracting sweat gland pores from an image including a skin marking; and

acquiring sweat gland pore information including position informationabout the sweat gland pore and directional information about the sweatgland pore for each of the sweat gland pores.

(Supplementary Note 16)

A storage medium storing a program that causes a computer to perform:

extracting sweat gland pores from an image including a skin marking; and

acquiring sweat gland pore information including position informationabout the sweat gland pore and directional information about the sweatgland pore for each of the sweat gland pores.

As described above, although the disclosure has been described withreference to the example embodiments, the disclosure is not limited tothe example embodiments described above. Various modifications that maybe understood by those skilled in the art can be made to theconfiguration or details of the disclosure within the scope of thedisclosure.

REFERENCE SIGNS LIST

-   -   1 . . . information processing apparatus    -   10 . . . CPU    -   12 . . . RAM    -   14 . . . storage unit    -   16 . . . input unit    -   18 . . . fingerprint imaging unit    -   20 . . . display unit    -   22 . . . common bus    -   102 . . . image acquisition unit    -   104 . . . image division unit    -   106 . . . sweat gland pore extraction unit    -   108 . . . direction detection unit    -   110 . . . error setting unit    -   112 . . . reliability acquisition unit    -   114 . . . registration unit    -   116 . . . matching unit    -   118 . . . determination unit    -   120 . . . ridge line drawing unit    -   1162 . . . position matching unit    -   1164 . . . direction matching unit

1. An information processing apparatus comprising: one or moreprocessors; and a memory storing instructions executable by the one ormore processors to: extract sweat gland pores from an image including askin marking; and acquire sweat gland pore information includingposition information about the sweat gland pore and directionalinformation about the sweat gland pore for each of the sweat glandpores, wherein the direction information is information indicating adirection obtained by averaging directions of valley lines on both sideslocated nearest to the center of gravity of the sweat gland pore.
 2. Theinformation processing apparatus according to claim 1, wherein theinstructions are executable by the one or more processors to further:acquire the direction information based on the directions of the valleylines on both sides of a ridge line where the sweat gland pore islocated.
 3. The information processing apparatus according to claim 1,wherein the instructions are executable by the one or more processors tofurther: extract the sweat gland pore based on information relating togradation of the image.
 4. The information processing apparatusaccording to claim 3, wherein the instructions are executable by the oneor more processors to further: extract an area of a predeterminedgradation range that fits in a closed ring in the image as the sweatgland pore.
 5. The information processing apparatus according to claim3, wherein the instructions are executable by the one or more processorsto further: extract an area of a predetermined gradation range that fitsin a ring partially opened in the image as the sweat gland pore.
 6. Theinformation processing apparatus according to claim 1, wherein theinstructions are executable by the one or more processors to further:set an error tolerance range for at least one of the positioninformation and the direction information.
 7. The information processingapparatus according to claim 1, wherein the image is a first image, andthe instructions are executable by the one or more processors tofurther: match first sweat gland pore information acquired on the firstimage and second sweat gland pore information acquired on the secondimage.
 8. The information processing apparatus according to claim 7,wherein first position information of the first sweat gland poreinformation and second position information of the second sweat glandpore information are matched.
 9. The information processing apparatusaccording to claim 7, wherein first direction information of the firstsweat gland pore information and second direction information of thesecond sweat gland pore information are matched.
 10. The informationprocessing apparatus according to claim 7, wherein the instructions areexecutable by the one or more processors to further: divide the imageinto a plurality of divided areas; and acquire reliability informationabout reliability of each divided area according to a number of thesweat gland pores extracted in the divided area, wherein the sweat glandpore information about the divided area having a predeterminedreliability or higher among the plurality of divided areas is matched.11. The information processing apparatus according to claim 10, whereinthe instructions are executable by the one or more processors tofurther: determine whether or not a target person from whom the firstimage has been acquired is a registrant from whom the second image hasbeen acquired, based on a matching result for each of the divided areasby the matching unit and the reliability information of the dividedarea.
 12. The information processing apparatus according to claim 1,wherein the position information is coordinate information of the centerof gravity of the sweat gland pore.
 13. The information processingapparatus according to claim 1, wherein the skin marking is afingerprint.
 14. An information processing method comprising: extractingsweat gland pores from an image including a skin marking; and acquiringsweat gland pore information including position information about thesweat gland pore and directional information about the sweat gland porefor each of the sweat gland pores wherein the direction information isinformation indicating a direction obtained by averaging directions ofvalley lines on both sides located nearest to the center of gravity ofthe sweat gland pore.
 15. A non-transitory storage medium storing aprogram that causes a computer to perform: extracting sweat gland poresfrom an image including a skin marking; and acquiring sweat gland poreinformation including position information about the sweat gland poreand directional information about the sweat gland pore for each of thesweat gland pores wherein the direction information is informationindicating a direction obtained by averaging directions of valley lineson both sides located nearest to the center of gravity of the sweatgland pore.